The stepper is generally a device for printing a predetermined pattern on a photo-resist (PR) which is sensitive to light. The above procedure consists of a few procedures as follows. First of all, there is provided a substrate on which a photo-resist is coated. On the substrate, a pattern film with a formed pattern is placed. Ultraviolet ray is canned onto the pattern film. The ultraviolet ray light-exposes through the pattern film the photo-resist in the shape same as the pattern. After the light-exposing work is done, a non-light exposed portion is chemically eliminated, thus printing a predetermined pattern.
In the present invention a variety of materials on which the photo-resist is coated is called a substrate. When a conventional circuit with fine pitches is manufactured, a parallel light stepper is generally used. The parallel light stepper costs a lot for its fabrication, and the area to be used is limited. The present invention is directed to manufacturing a stepper with a linear light source generator which uses a lenticular, not using the expensive parallel light stepper, thus substituting the related expensive equipment.
The stepper generally comprises an optical system configured to process the light of the light source by means of a variety of lens arrangement, a table, other transfer devices, a cooling device and a controller. The stepper according to the present invention is a stepper equipped with a linear light source generator which uses a lenticular. The linear light source generator comprises a light source and a lenticular system.
The light-exposing work of the stepper according to the present invention is performed based on a relative transfer with respect to the linear light source generator and the pattern film or the photo mask. The stepper according to the present invention is characterized in that the optical system used in the typical stepper is substituted with a linear light source generator of the present invention. The linear light source generator of the present invention uses a lenticular.
When the stepper with the linear light source generator of the present invention is used, the photo-resist layer may be light-exposed accurately and precisely in the same pattern as the pattern film or the photo mask. Even the pattern with fine pitches may be light-exposed, and even when the thickness of the photo-resist layer is relatively thick, a clear light exposure may be possible. The linear light source generator of the present invention is directed to substituting the complicated optical system made by processing and engaging larger lens with a simpler structure. For the sake of micro-sized and precise light exposure, a complicated and large optical system is necessary. In this case, the effective area for light-exposing the substrate is actually a palm size in the region being in proximity to the center of the optical system. However, the present invention may provide the effective area as large as desired using a simple lenticular system. Most of the thickness of the lenticular system of the present invention are within 1 mm. With the current science standard, there is a physical limit in manufacturing the larger lenses belonging to the optical system. Even with the current science standard, there is not a limit in making the lenticular larger in a simple way. As one of the biggest advantages, the stepper with the linear light source generator of the present invention is strong against the vibrations. The stepper of the present invention is characterized in that an accurate light exposure may be possible even under vibration environments.